1. Field of the Invention
The present invention relates to a lens device and a vibration-proof adapter and in particular to a lens device and a vibration-proof adapter that has a vibration-proof lens for correcting a blurred image resulted from vibration on a camera when a TV camera is used for a sports broadcast or on a scaffold outdoors.
2. Description of the Related Art
Conventionally, a camera having such a vibration-proof lens supports the vibration-proof lens movably inside a surface perpendicular to an image-taking optical axis in a lens barrel of the camera. When the camera is vibrated, the vibration-proof lens is moved by an actuator in a direction of canceling the vibration to correct a blurred image. Such a camera has a lock mechanism for fixing the vibration-proof lens onto the lens barrel to prevent the vibration-proof lens from being moved and damaged when the camera is conveyed.
Japanese Patent Application Publication No. 2000-2901 discloses a lock mechanism in which a lens holding frame of a vibration-proof lens is clamped and held by rotating an operating ring to lock the vibration-proof lens onto a lens barrel. However, in this lock mechanism, when the operating ring is moved by mistake during conveyance of a lens device, the vibration-proof lens may be unlocked. Further, Japanese Patent Application Publication No. 2000-39638 discloses a lock mechanism in which a lens holding frame of a vibration-proof lens is pressed and held by sliding a lock ring to lock the vibration-proof lens onto a lens barrel. In this lock mechanism, since a lens cap is attached on the lens barrel, the vibration-proof lens is conveyed while being positively locked. However, when the lens cap fails to be placed thereon, it is not possible to guarantee a locking state of the vibration-proof lens.
Furthermore, in these lock mechanisms, every time the lens device is attached and detached to and from a camera main body, it is necessary to operate the operating ring and the locking ring to lock and unlock the vibration-proof lens. Hence, more operational ease has been demanded. Such a problem has been also found on a vibration-proof adapter placed between a lens device and a camera main body to correct a blurred image.
Japanese Patent Application Publication No. 6-189181 discloses an intermediate adapter (vibration-proof adapter), which is detachably attached between a camera and a lens device. The vibration-proof adapter has a variable vertex angle prism corresponding to a vibration-proof lens, a vibration detecting sensor, a variable vertex angle prism driving circuit, and so on therein. The variable vertex angle prism driving circuit moves the variable vertex angle prism and decenters an optical axis according to vibration information detected by the vibration detecting sensor. Thus, a blurred image is corrected.
Japanese Patent Application Publication No. 11-284900 discloses a usage pattern in which a lens device is connected to the front of a vibration-proof device (vibration-proof adapter) and a camera is connected to the back of the vibration-proof adapter.
However, Japanese Patent Application Publication Nos. 6-189181 and 11-284900 fail to disclose a connecting structure for connecting a vibration-proof adapter to a camera. A vibration-proof adapter is hard to hold because it weighs about 3 to 4 kg with a thin shape. Hence, it is necessary to connect a vibration-proof adapter to a camera or a lens device while putting a hand on a connecting surface with the camera or a connecting surface with the lens device. Thus, a hand may be caught between the vibration-proof adapter and the camera or between the vibration-proof adapter and the lens device.
The present invention has been developed in view of the above-described circumstances, and has as its object the provision of a lens device and a vibration-proof adapter that cause no operating error on a lock mechanism of a vibration-proof lens and achieve operational ease for the lock mechanism.
Another object of the present invention is to provide a vibration-proof adapter connected to a camera or a lens device with safety and ease.
In order to attain the above objects, the present invention is directed to a lens device to be connected to a camera main body, the lens device correcting a blurred image resulted from vibration of the camera main body, the lens device comprising: a lens barrel; a vibration-proof lens movably arranged in the lens barrel, the vibration-proof lens being moved to correct the blurred image; a joint with which the lens device is connected to the camera main body; and a lock mechanism which locks the vibration-proof lens, the lock mechanism having a switch which detects connection and disconnection of the joint with the camera main body, wherein the lock mechanism unlocks the vibration-proof lens when the switch detects the connection of the joint with the camera main body, and the lock mechanism locks the vibration-proof lens when the switch detects the disconnection of the joint from the camera main body.
According to the present invention, since the switch of the lock mechanism is provided on the joint for the camera main body, the switch is operated in response to attachment and detachment of the camera to/from the joint. Therefore, since the vibration-proof lens is automatically locked and unlocked, it is possible to eliminate the inconvenience of operating the lock mechanism for each attachment and detachment.
Preferably, the switch is provided on a recess of the joint, and the switch is not operated by mistake when the lens device is conveyed.
Further, in order to attain the above objects, the present invention is directed to a vibration-proof adapter to be connected between a camera main body and a lens device, the vibration-proof adapter correcting a blurred image resulted from vibration of at least one of the camera main body and the lens device, the vibration-proof adapter comprising: a lens barrel; a vibration-proof lens movably arranged in the lens barrel, the vibration-proof lens being moved to correct the blurred image; a joint with which the vibration-proof adapter is connected to the camera main body; and a lock mechanism which locks the vibration-proof lens, the lock mechanism having a switch which detects connection and disconnection of the joint with the camera main body, wherein the lock mechanism unlocks the vibration-proof lens when the switch detects the connection of the joint with the camera main body, and the lock mechanism locks the vibration-proof lens when the switch detects the disconnection of the joint from the camera main body.
The present invention is also directed to a vibration-proof adapter to be connected between a camera main body and a lens device, the vibration-proof adapter correcting a blurred image resulted from vibration of at least one of the camera main body and the lens device, the vibration-proof adapter comprising: a lens barrel; a vibration-proof lens movably arranged in the lens barrel, the vibration-proof lens being moved to correct the blurred image; a joint with which the vibration-proof adapter is connected to the lens device; and a lock mechanism which locks the vibration-proof lens, the lock mechanism having a switch which detects connection and disconnection of the joint with the lens device, wherein the lock mechanism unlocks the vibration-proof lens when the switch detects the connection of the joint with the lens device, and the lock mechanism locks the vibration-proof lens when the switch detects the disconnection of the joint from the lens device.
According to the present invention, since the switch of the lock mechanism is provided on the joint for the camera main body or the joint for the lens device, the switch is operated in response to attachment and detachment of the camera main body or the lens device to/from the joint. Therefore, since the vibration-proof lens is automatically locked and unlocked, it is possible to eliminate the inconvenience of operating the lock mechanism for each attachment and detachment.
Preferably, the switch is provided on the recess of the joint, and the switch is not operated by mistake when the vibration-proof adapter is conveyed.
Furthermore, in order to attain the above-mentioned objects, the present invention is directed to a vibration-proof adapter which is connected between a camera and a lens device, the vibration-proof adapter being characterized in that a grip is attached on a part other than connecting surfaces for the camera and the lens device on a main body case of the vibration-proof adapter.
According to the present invention, the grip is attached on the part other than the connecting surfaces to be connected to the camera and the lens device. Thus, a hand is not caught between the vibration-proof adapter and the camera or the lens device, thereby improving safety.
Preferably, a gripping part of the grip is placed on a position shifted from a center of gravity of the vibration-proof adapter to the lens device or the camera. Thus, when the gripping part is held, the vibration-adapter is lifted while being inclined. Therefore, for example, when the vibration-proof adapter and the camera is connected to each other by engaging hooks, the hooks are readily engaged to each other due to inclination of the vibration-proof adapter, thereby making connection with ease.
More preferably, the grip is retractable in a receiving part provided at the main body case, and the grip does not become an obstacle or is not in contact with the lens device when it is not used.